Member for electrophotography, developing apparatus, and electrophotographic apparatus

Abstract

Provided is a member for electrophotography that enables stable formation of a high-quality electrophotographic image even when used as a developing member over a long period of time. The member for electrophotography includes: a support; an electro-conductive elastic layer on the support; and a plurality of electrically insulating domains on the electro-conductive elastic layer, in which a surface of the member for electrophotography includes surfaces of the electrically insulating domains and an exposed portion of the electro-conductive elastic layer free of being covered by the electrically insulating domains, and in which the electrically insulating domains each contain a resin having a specific structure.

What is claimed is: 
     
       1. A member for electrophotography, comprising:
 a support; 
 an electro-conductive elastic layer on the support; and 
 a plurality of electrically insulating domains on the electro-conductive elastic layer, wherein 
 a surface of the member for electrophotography includes surfaces of the electrically insulating domains with an exposed portion of the electro-conductive elastic layer free of being covered by the electrically insulating domains, and 
 the electrically insulating domains contain a resin having a structure represented by formula (1):
   A n R  (1)
 
 
 where n represents an integer of 2 or more, R represents a linking group that links n pieces of A and the linking group R contains an oligomer component of at least one resin selected from the group consisting of polyurethane, polyester, an epoxy resin, and polybutadiene, and A represents a structure represented by formula (2): 
 
       
         
           
           
               
               
           
         
         where R 1  represents a hydrogen atom or a methyl group, and symbol “*” represents a bonding site with the linking group R. 
       
     
     
       2. A member for electrophotography according to  claim 1 , wherein (M2/M1)*100≤15
 where M2 represents a mass of a residue obtained by subjecting the electrically insulating domains having a mass M1 to reflux in a Soxhlet extractor for 36 hours using methyl ethyl ketone as a solvent, and removing the methyl ethyl ketone from the resultant extract solution. 
 
     
     
       3. A member for electrophotography according to  claim 1 , wherein the electrically insulating domains are each formed in a convex shape with respect to a surface of the electro-conductive elastic layer. 
     
     
       4. A member for electrophotography comprising:
 a support; 
 an electro-conductive elastic layer on the support; and 
 a plurality of electrically insulating domains on the electro-conductive elastic layer, wherein 
 a surface of the member for electrophotography includes surfaces of the electrically insulating domains with an exposed portion of the electro-conductive elastic layer free of being covered by the electrically insulating domains, and 
 the electrically insulating domains contain a resin having a structure represented by formula (1):
   A n R  (1)
 
 
 where n represents an integer of 2 or more, R represents a linking group that links n pieces of A, and A represents a structure represented by formula (2): 
 
       
         
           
           
               
               
           
         
         where R 1  represents a hydrogen atom or a methyl group, and symbol “*” represents a bonding site with the linking group R, and 
         the linking group R has at least one of structures represented by formulae 3-1, 3-3, 3-4, 3-5, 3-8 and 3-9: 
       
       
         
           
           
               
               
           
         
         where m2 represents an integer of 15 to 60, 
       
       
         
           
           
               
               
           
         
       
     
     
       5. A developing apparatus, comprising a developing member, the developing member comprising:
 a support; 
 an electro-conductive elastic layer on the support; and 
 a plurality of electrically insulating domains on the electro-conductive elastic layer, wherein 
 a surface of the member for electrophotography includes surfaces of the electrically insulating domains with an exposed portion of the electro-conductive elastic layer free of being covered by the electrically insulating domains, and 
 the electrically insulating domains contain a resin having a structure represented by formula (1):
   A n R  (1)
 
 
 where n represents an integer of 2 or more, R represents a linking group that links n pieces of A and the linking group R contains an oligomer component of at least one resin selected from the group consisting of polyurethane, polyester, an epoxy resin, and polybutadiene, and A represents a structure represented by formula (2): 
 
       
         
           
           
               
               
           
         
         where R 1  represents a hydrogen atom or a methyl group, and symbol “*” represents a bonding site with the linking group R. 
       
     
     
       6. A developing apparatus comprising a developing member, the developing member comprising:
 a support; 
 an electro-conductive elastic layer on the support; and 
 a plurality of electrically insulating domains on the electro-conductive elastic layer, wherein 
 a surface of the member for electrophotography includes surfaces of the electrically insulating domains with an exposed portion of the electro-conductive elastic layer free of being covered by the electrically insulating domains, and 
 the electrically insulating domains contain a resin having a structure represented by formula (1):
   A n R  (1)
 
 
 where n represents an integer of 2 or more, and R represents a linking group that links n pieces of A, and A represents a structure represented by formula (2): 
 
       
         
           
           
               
               
           
         
         where R 1  represents a hydrogen atom or a methyl group, and symbol “*” represents a bonding site with the linking group R, and 
         the linking group R has at least one of structures represented by formulae 3-1, 3-3, 3-4, 3-5, 3-8 and 3-9: 
       
       
         
           
           
               
               
           
         
         where m2 represents an integer of 15 to 60,